van Marthens E
Biol Neonate. 1977;31(5-6):324-32. doi: 10.1159/000240983.
The in utero growth rates have been determined for the body, brain, and the placenta in the rat. The accumulation of cell number (DNA content) and protein content in the cerebrum and the placenta were investigated during normal development. When rats were exposed to a severe reduction in protein/calorie intake during the first 10 days of pregnancy and the fetal growth rates were compared to those of the normal control animals, highly significant differences were observed. Pregnant rats, which were restricted in their protein/calorie intake during the early part of pregnancy, significantly prolonged the gestation time. When this increase of in utero time is taken into consideration and the offspring are compared at the time of natural birth, the data presented demonstrate the possibility of in utero catch up growth. The variations, in fetal development within the same litter and across litters, demonstrate a considerable plasticity during normal development in utero.
已测定大鼠体内、大脑和胎盘在子宫内的生长速率。在正常发育过程中，研究了大脑和胎盘细胞数量（DNA含量）和蛋白质含量的积累情况。当大鼠在怀孕的前10天蛋白质/热量摄入量严重减少，并将胎儿生长速率与正常对照动物的生长速率进行比较时，观察到了非常显著的差异。在怀孕早期蛋白质/热量摄入受限的怀孕大鼠，其妊娠期显著延长。当考虑到子宫内时间的这种增加，并在自然分娩时对后代进行比较时，所呈现的数据表明了子宫内追赶生长的可能性。同一窝内以及不同窝之间胎儿发育的差异，表明在子宫内正常发育过程中具有相当大的可塑性。
